Less than 10% of eligible older patients receive an ICD after a myocardial infarction

30th June 2015

361

Sean D Pokorney (Division of Cardiology, Duke University Medical Center, Durham, USA) and others report in the Journal of the American Medical Association (JAMA) that only 8.1% of older patients who are eligible to receive an implantable cardioverter defibrillator (ICD) after a myocardial infarction actually do so. The authors also found that older age did not appear to affect the mortality benefit that is associated with ICD implantation.

Pokorney et al report that, according to US guidelines, ICDs should be considered for primary prevention of sudden cardiac arrest in patients who have an ejection fraction of 35% or less “despite being treated with optimal medical therapy for at least 40 days after a myocardial infarction”. However, they add there is evidence of underuse of ICDs in this population overall and that “uncertainties regarding ICD effectiveness”-as well as other factors-may discourage physicians from using ICDs in older patients.

Therefore, Pokorney et al examined a large community-based sample of post-myocardial infarction patients who were eligible for ICD implantation and who were aged older than 65 years to determine how many were actually receiving an ICD. They also sought to identify the factors associated with a patient receiving an ICD within one year of having a myocardial infarction.

Using data from ACTION Registry-GWTG (National cardiovascular data registry acute coronary treatment and interventions outcomes network registry-get with the guidelines), the authors reviewed information for 10,318 post-myocardial infarction patients with an ejection fraction of 35% or less and who were aged 65 or older (mean age 78 years). They found that at one year after a myocardial infarction, only 8.1% of these patients had received an ICD. Pokorney et al report that, in a multivariate analysis, “Among patient characteristics, older age, female sex, and end-stage renal disease were most strongly associated with lower likelihood of one-year ICD implantation”.

They found that, in the overall study population (in line with the results of previous studies), patients who received an ICD by one year had a significantly lower two-year mortality rate than those who did not receive a device. The authors comment: “We conducted prespecified subgroup analyses by age and sex; 44% of our study population were 80 years or older and 46% were female. The relationship between ICD implantation and mortality was similar among patients 80 years or older and younger than 80 years as well as among male and female patients.”

The authors note that the use of an ICD to prevent sudden cardiac death “may have limited effect on overall mortality in patients older than 80 years” and that the decision to implant an ICD may “shift death from a sudden event to a more gradual and comorbid process” in these patients. Therefore, they state discussions about whether or not to implant an ICD in an older patient must take into context the “patient’s quality of life, treatment goals, and preferences”. However, Pokorney et al say: “Age alone should not be exclusion for ICDs and better risk prediction tools validated among older patients are needed.”

In an accompanying commentary, Robert G Hauser (Minneapolis Heart Institute, Abbott Northwestern Hospital, Allina Health, Minneapolis, USA), writes: “Even though the use of ICDs for primary prevention may not seem to make as much sense for an 80-year-old patient as it does for a patient in his or her 50s or 60s, an older patient at risk of sudden cardiac death should have the same opportunity to choose potentially lifesaving therapy.”